<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<style type="text/css">
			.box{
				width: 400px;
				height: 300px;
				background-color: orange;
				padding-left: 10px;
			}
			/*padding会把盒子整体撑大，padding撑大多少，width和height就要减多少*/
			.inner{
				width: 350px;
				height: 250px;
				background-color: green;
			}
		</style>
	</head>
	<body>
		<div class="box">
			<div class="inner">
				
			</div>
		</div>
	</body>
</html>
